Abstract: An activatable time-temperature indicator system useful in tracking the thermal exposure history of a temperature-sensitive perishable product and providing a visually-distinct signal, such as a change in color density, at the expiration of a predetermined time-temperature integral comprises a first element, such as a direct thermal printing label (11), comprising a composition (13) having at least a first co-reactant of a color-forming reaction. A second, activator element, such as an adhesive tab (21) capable of being affixed to the label element, comprises an activator component (25), such as a second co-reactant of the color-forming reaction or a solubilizing agent for prompting the interaction of the co-reactants of the label composition. The activator tab element is affixed to the label composition to activate for reaction at ambient conditions the normally high-temperature color-forming composition (13) of the label at about the same time as the label is affixed to the perishable product.

Abstract: A time-temperature indicator label for measuring the length of time to which a product has been exposed to a temperature above a pre-determined temperature is provided. The period of time of exposure is integrated with the temperature to which the indicator is exposed. The label is a composite of a plurality of layers adapted to be adhered at its underside to a product container. The label includes a printable surface layer, a longitudinal wicking strip that is adhered underneath the surface layer substantially at the opposite extremities only of the wicking strip and a lower substrate layer forming an envelope with said surface layer. A heat-fusible substance, which melts and flows above a pre-determined temperature, is applied on the surface of the wicking strip contiguous to at least one of the ends of the wicking member. When the heat-fusible substance is exposed to a temperature above the pre-determined temperature, the heat-fusible substance flows along the length of the wicking member.

Abstract: A time-temperature indicator label for measuring the length of time to which a product has been exposed to a temperature above a pre-determined temperature is provided. The period of time of exposure is integrated with the temperature to which the indicator is exposed. The label is a composite of a plurality of layers adapted to be adhered at its underside to a product container. The label includes a printable surface layer, a longitudinal wicking strip that is adhered underneath the surface layer substantially at the opposite extremities only of the wicking strip and a lower substrate layer forming an envelope with said surface layer. A heat-fusible substance, which melts and flows above a pre-determined temperature, is applied on the surface of the wicking strip contiguous to at least one of the ends of the wicking member. When the heat-fusible substance is exposed to a temperature above the pre-determined temperature, the heat fusible substance flows along the length of the wicking member.

Abstract: An accurate monitoring of the conditions of a perishable product is achieved by integrating two indicator types - a primary indicator which develops a color change as a result of cumulative time-temperature exposure and a threshold second indicator - into a single device. The combination of the two indicators in the same indicator device provides a human readible signal that gradually and irreversibly develops color as a function of time and temperature and more closely monitors the actual condition of a deteriorative product than does a single indicator. Important features of this integrated monitoring device are reliability and printability. The primary indicator in the system is assisted in color development by the secondary indictor that is set to trigger at a predetermined temperature. When this temperature is reached or exceeded both indicator mechanisms function in an additive mode to cause a break in the typical Arrhenius curve, which a primary indicator alone produces.

Abstract: An improved decal and method of decal manufacture includes a base sheet of polyethylene (polymeric) type material with a urethane (polymeric) high solids content carrier layer in the shape of the decal printed thereon. The graphics for the decal are printed on the carrier layer and a high tack adhesive is then overprinted on the ink layers forming the completed decal. The decal is applied to a surface and the base sheet is separated from the applied decal.

Abstract: An improved decal and method of decal manufacture includes a base sheet of polyethylene (polymeric) type material with a urethane (polymeric) high solids content carrier layer in the shape of the decal printed thereon. The graphics for the decal are printed on the carrier layer and a high tack adhesive is then overprinted on the ink layers forming the completed decal. The decal is applied to a surface and the base sheet is separated from the applied decal.

Abstract: A dry transfer decal includes a flexible carrier layer as a substrate with a high adhesion characteristic urethane layer on the substrate. Ink layers are printed on the urethane layer and a high tack adhesive is screened over the printed ink layers. The decal may be transferred from the substrate to a surface by applying a local pressure through the substrate on the decal thereby impinging the decal onto the surface. Specific formulations for the urethane layer and the various ink layers are disclosed.

Abstract: A method for producing a multicolor heat transfer decal comprises printing specially formulated thermoplastic inks successively onto a pre-release coated carrier sheet. The inks give optimum print quality using plastic printing plates and a rotary letterpress or flexographic printing process.